We explore the application of terrestrial radar as a tool for imaging topography on Momotombo volcano, Nicaragua. A major feature of the edifice is an incised lava flow channel (possibly created by the 1904 eruption) that measures ~150m in width and up to 60m in depth. This feature is unusual because most lava channels are constructional in nature and constrained by levees on their margins. The radar elevation model was used alongside a TerraSAR-X/TanDEM-X DEM to help create a topographic time series. We consider the possibility that the channel was formed during the 1904 eruption by thermal and / or mechanical erosion. We aim to quantify the energy required to create the observed topography by merging this topographic time series with existing field observations and mathematical models of erosion via lava flow.